template <typename T>
BinNodePosi(T) 
BST<T>::connect34(
	BinNodePosi(T) a, BinNodePosi(T) b, BinNodePosi(T) c,
	BinNodePosi(T) T0, BinNodePosi(T) T1, BinNodePosi(T) T2, BinNodePosi(T) T3)
{
	a->lc = T0;
	if(T0) T0->parent = a;

	a->rc = T1;
	if(T1) T1->parent = a;
	this->updateHeight(a);

	c->lc = T2;
	if(T2) T2->parent = c;

	c->rc = T3;
	if(T3) T3->parent = c;
	this->updateHeight(c);

	b->lc = a;
	a->parent = b;
	b->rc = c;
	c->parent = b;
	this->updateHeight(b);

	return b;
}